1. Field of the Invention
This invention relates generally to alignment systems for the front end of motor vehicles, and particularly to a system for realigning motor vehicle front ends constructed with non-adjustable suspensions such as those employing McPherson struts.
2. Description of the Prior Art
The current trend towards smaller automobiles has resulted in development of a vehicle construction generally referred to as "uni-body" or unitized body construction. One of the features of such construction is the use of non-adjustable front end suspensions built around an upstanding elongated longitudinally extendable spring-biased strut anchored directly to the sheet metal of the vehicle body at the upper end and supporting one of the front wheels at the lower end. These struts are known generally as the McPherson strut. The use of such front end suspension systems, while currently restricted primarily to many popular models of cars of foreign manufacture, is expected to increase greatly in the next few years due to adoption of the unitized body mode of construction by United States automobile manufactures.
A disadvantage of the unitized body construction employing non-adjustable front end suspensions is that if the vehicle is afflicted with impact damage to the front end thereof, the struts must first be realigned before the body metal can be repaired and the unitized body construction restored, since it is the body metal itself which holds the struts in place on the vehicle. Currently, body and fender shops will either insert a fluid jack between the upper ends of the struts in order to push same apart, or will connect a turn buckle between such upper ends of the struts in order to pull the ends toward one another. These methods, however, are inherently inaccurate, and further are not capable of providing relative movement between the struts, which relative movement is often necessary to restore the struts to positions in accordance with factory specifications.
It is generally known to use either a fluid-operated or mechanical jack in a suitable manner to straighten vehicle frames and body metal. For example, U.S. Pat. No. 3,765,219, issued Oct. 16, 1973 to W. N. Easom, Jr. discloses a wheel alignment device which straightens wheel suspension beams and includes a bifurcated frame between the sides of which is pivotally mounted a fluid-operated or mechanical jack. Further, additional examples of body and frame pulling devices can be found in U.S. Pat. Nos. 3,577,881, issued May 11, 1971 to E. J. Markovics; 3,817,081, issued June 18, 1974 to R. Morski et al; and 3,835,692, issued Sept. 17, 1974 to R. B. Hoffman.